Projectile



Dec. 17, 1.946. H. F. Ros-r 4El AVL PROJECTILE Filed sept. 1e, .1942

MTW

Rpw NEM Svenss on Het Fev Hoxr Patented Dec. 17, 1946 2,412,695* I PRJECTE lg'e Fabian Rost, Djursholni, Per Hairy Elia-s C1aesson,Jakobsberg, and RiolfAl-bin Svensson,

Angb'y, Sweden Application 'september 16, raiz, serial No. 458,490 In Sweden January 7, 1942' 'The 'present invention relates generally to lprojectiles and vparticularly vto devices for igniting lnirsti'ngV charges Vof projectiles, for example rie grenades, grenades for ltrench mortars and guns,

aerial bombs to Ybe dropped from airplanes and l ing 'provided lwith steering ns for guiding the A 'projectile according tothe invention comprises in combination a 'casing having straight external steering hns ior guiding the projectile inits trajectory, a bursting charge with its detonator; fuse and fuse cap within said casing, a striker head with fir-ing pin -at an operable distance froinsa'id Yfuse cap, a stiff precursor of desired'length and ejeetable from the casing, means to Yeject the said precursor, said precursor being adapted upon ejection to be so rigidly coupled tothe said strikerfhead so that the striker head and Vits irng pin are operated upon impact of the-front par-t of said precursor against the target; and means wholly within thev projectile to cause delayed release of the said ejecting means vfor the ejection of said precursor at a chosen time vafter the projectile has departed from its starting place and after the projectile has "been stabilized with its striker head .forward in its predetermined trajectory.

When the ejected front .part of the precursor strikes the earth or the target, the striker head with 4ring pin or the firing device is caused to detonate the charge.

The release `of the precursor can take place infseveral Ways of which only a few will be here described. The invention is, however, not limited lto `the embodiments here shown, but refers generally to all grenades, projectiles and bombs that shall be caused to explode immediately be'- fore Vthe :projectile proper strikes the target.

-Bymeans of the invention a substantially ini creased -action on living targets, vehiclesi ar= vmoured cars, tanks and the like can be obtained as -well -as on'buildings and the like that shall be wrecked or be made unsuitableior-further use. V Thevprinciple' of the invention will be further understood-from the attached drawing of which- -Fig.-1is a vertical Vsection of .a service fuse of 42 a projectile according toene embodiment ci! the invention.

Fig. 12 is a `horizcnta1 view of a section of the fuse showing an embodiment ofthe invention comprising safety devices and devices for release oi'faprecursor-ejectable from the ifuse.

Fig. Bis la vertical section at about '90 -to 'th section di the fuse-'shown in Fig'. l.' i

Fig. 4'v vis a vertical section or anotherernbodi nient o'f the lower part ofthe1;irecursor or tube shown' `in Fig. l' with Vmodified means of release of the precursor. I

Fig. 5 Vis a horizontal section 'of the device lshown inFig. 4.-

Fig. 6V Vrepresents a view partly in section of a grenade or aerial bomb according to the in'v'en- .tion andprovided 'with casing, steering Auns and bursting' charge.

In Figs. 1`3 showing alfuse fora grenade .for a trench mortar, the pin I serves as safety device during-transportation, by means of which .pin the ,piston `2 is Ykept in locked position.. The .piston 2 is kept in normal position by the safety springt which .serves Vas safety device at the Vloadingoperation.

Due to l the jerkat the .moment of firing .the safetyspring 3 is knocked out of vshapeallowing. the piston-2 to be thrown backwards so that the rotor-4 with its fusecap 5 and fuse I5I arefreed. The rotor :can be `turned by means -of the spiral spring -1 attached iat one fend to the central tube Sand-at theother end being fastened to a pin 8 attached to the rotor. When said pin 8 'upon yrota-tion -oi the rotor meets .the ringpin `9, vthe upper fuse cap '5 and yfuse I:5I will be located exactly -underf'the'ring .pin and also exactly over afuse II located'in the fuse body I0. The cenn tral tube l is attached to the fuse body I0 .by means of kthe fastening bolt l2. The ringpin .9 is attached to the strikerhead I3 kept inits normal position by the spring Ill which serves as safetydevice in .the trajectory of the grenade.

The safety-spring I4 is securely held between :the upper iixed -partoftheceni-,raltubel andthe striker head.

Thevcentralrtube Bis at. its'upper part provided with ytwo kslits for vguiding the striker head by means of thefsinall pistons .I1 `whichxlcy means of spiralsprings I8 are pressing against the movable precursor Iii. By means of the vsmall pistons -I-'l `the .striker headiis prevented from turning with respect tothe central tube 6, whichsis .provided With-'a swelling '20 :resting on thefuse body lfto prevent .the centraltube from' moving axially due to acceleration at the ejection of the projectile from the mortar barrel.

On the upper part of this swelling 20 there is a washer I5 which by means of a lip protruding into one of the slits I6 is prevented from turning with respect to the central tube. On the washer I5 is fastened, the pin- 2| about which the lever 22 is turnable. Th'eother end offlever 22 is normally resting against stop pin 8 on the rotor 4. The lever is provided with a conical tip 23 entering into a corresponding hole of the pre-v cursor I9 by means of which said precursor is locked in its normal position shownin the draw-` ing. Within the precursor I9 there is located a nspiral spring 24 whichrhas a tendency of ejecting the precursor, but is prevented from said ejecting action by the stud or tip 23 of the lever 22. The lower part of the precursor I9 is provided with a swelling 25 partly to steer the pre-` cursor and partly to serve as a stop against' the upper part of the striker head, when the precursor is ejected. The vdevice shown in Figs. 1-3r operates in the following way. The safety pin I is pulled out before introducing the projectile in the barrel of the mortar. By means of the pin I the safety piston 3 and the precursor I9 are normally locked. At the ring the safety spring 3 is knocked out ofshape allowing the piston 2 to be thrown backwards. Hereby the rotor 4 becomes free, but safety against operation of the rotor within the barrel is obtained thereby that during the greater part -of the passing of the projectile through the barrel the rotor is so heavily pressed against the fuse body that the spring 1 cannot move the rotorff' f When the acceleration of -the projectile after leaving the gun barrel is sufciently lessened and retardation on account f the air resistance takes place, the rotor begins to turn until the fuse cap vis located in front of the firing pin 9. When the rotor starts to turn, the pin 8 leaves its normalposition, and the lever 22 becomesv free to turn about its pin 2 I. f

The stud or tip 23 on the lever 22 has been given such a conical angle that when the acceleration and the air resistance on the front part of the precursor have been sufficiently lessened the force of the spring 24 isv sufficient to push the lever 2| and its conical stud 23 to the side, whereafter' the precursor is ejected until its lower swelled part is stopped by the inner upper wall of the striking head and locked due to the conical shape of the upper part of the lower swelled part of the precursor. Hereby the lower part of the precursor has passed the small pistons I'I which now protrude behind the bottom of the precursor and lock it in its forward operating position to the striker head.

When the projectile is arriving at the target, itis the front part of the precursor that hits the earth`or the target. As the precursor now is locked to the striker head, said head together with the firingpin'v is pushed towards the fuse cap5 and fuse I5I, which fires the fuse II. The latter res the detonator 26, which is screwed into the top nut 2l and vcarries the detonation further to the bursting charge inside the casing. In Fig. 4 and Fig. 5 another embodiment of the locking device of the precursor is shown. Instead of the lever 22 and the stud 23 shown in Fig. 2, two studs 2B and 29 are fastened to the central tube "6. The precursor is .at its rear end provided with'an opening 39 of suitable form. 'vThe precursori is prevented.from" being ejected by the 4 upper stud 28 the protruding part of which normally rests in an upper notch of the opening 30.

Upon firing the precursor is thrown backwards on account of the acceleration of the projectile and due to the inertia of the precursor. The precursor is thereby forced to turn, because the low- Ver stud 29 engages the inclined wall 3l of the precursor sothat the precursor is freed from engagement with the upper stud.

When the acceleration and the air resistance are sufficiently lessened, the spring 24 can eject the precursor, as above described with reference i to Figs. 1-3, and the projectile will be fully armed before hitting the target.

The embodiments shown Vin Figures 1.5 refer to projectiles for trench mortars, whereby the projectile is provided with ns so arranged that the projectile follows the trajectory without rotating. It is, however, understood that the invention can also be used on projectiles provided with fins and fired from guns with smooth bores. -It Vcan also beused in aerial drop bombs without rotation. The action of release of the precursor must in each case be determined under consideration `of the initial acceleration, length of trajectory. retardation, etc., of the projectile,fsaid release to take place only after the projectile has been stabilized with its striker head forward in its deiinite trajectory; pyrotechnical devices can be used both for delaying the ejection of the precursor and for its ejection.

In Fig. 6 element 6I is the casing of a grenade or aerial bomb. Elements (i2 are steering fins. Element "63 is a bursting charge-in the center of which a fixed pipe 6 is located, and inside which pipe theprecursor I9 is arranged to be projected by means of a spring 24 as shown in Fig. 1.

.Instead of using spring pressure to eject the precursor, anyl other force can be used either combined with the acceleration at the firing or without same. K The rear end of the precursor I9 can thus be'shaped as a piston within the central tube Yfi, and a small powder charge can be placed at the bottom of tube 6. According to another embodiment, the device can be provided with a time fuse adapted to start operating at the firing of the projectile. The time fuse is previously adjusted to operate a pyrotechnical device which res, for example, a powder charge, after the projectile has passed the greater part of thetrajectory, for example', 50`to v100 meters from the target, whereby the rear part of the precursor in the shape of a piston is pressed outwards, until the small pistons I1 lock the precursor in its operating position before striking the target. The central tube 6 and the precursor I9 can eventually pass through the whole body of the projectile and be combined with a time fuse, for example, in the form of a light-tracer charge, thev sizev of which is so calculated that after a certainy number of seconds the re cap and a small powder charge is fired, whereby the piston pushes the precursor'toits operating position. vIn order to obtain the'explosion at a suitable distance before or above the target, the precursor can be` made considerably longer than shown on the drawing by making them composed of several parts in telescopic form, which parts upon delayed'ring of a powder charge or corresponding means will be pushed out and interlocked to form a single long precursor. In order notV to impair the stability ofthe ordiynarytrajectory'of the projectile, the front part of the precursor can be filled with a heavy weight.

for example lead, which will act as stabilizing agent on both the precursor and on the projectile as a whole after the precursor has been ejected. The heavy front part of the precursor will also lessen its tendency to vibrate due to side wind pressures.

According to the present invention the construction of a fuse according t Figs. 1-3 with a precursor I9 can be used in combination with aerial drop bombs with the following modification. As no acceleration step for releasing of the rotor d takes place when a bomb is released from a bombing machine, the piston 2 and safety spring 3 are suppressed. Instead of spring 'I for turning the rotor 4, the rotor can be provided with a cogwheel xed to the outer side of the rotor. A shaft with a small cogwheel to engage the larger cogwheel on the rotor is attached to a washer` fixed to the central tube 6. The shaft of the small cogwheel is coupled to a spiral spring 0r clockwork, which has a tendency to drive the cogwheels andthe rotor. The safety pin I holds the precursor I9 and the rotor 4 in normal position during transports and handling.

The device operates in the following way. Upon release of the bomb from the bombing machine the pin I is automatically pulled out, thereby leaving the precursor and the rotor free to move. The clockwork acting on the rotor through the cogwheels begins to move the rotor until the fuse cap 5 is in front of the re pin 9. Simultaneously the precursor I9 has been released and ejected and coupled to the striker head I3 as previously described. By choosing the proper size of the cogwheels a suitable time can be obtained before the fuse is fully armed after the bomb has fallen a su'icient safe distance from the bombing machine and has been stabilized in its trajectory.

What we claim is:

1. A projectile comprising in combination, a casing having straight external steering ns for guiding the projectile in its trajectory, a bursting charge, a detonator for said charge, a fuse and a fuse cap al1 within said casing, a striker head including a ring pin at an operable distance from said fuse cap, a stiff precursor of desired length and projectable from the casing. means to project the said precursor, means t0 couple said precursor, upon its projection, so rigidly to said striker head that the latter and its ring pin are operated upon impact of the front .part of said precursor against the target, and

means wholly within the projectile to delay the operation of said projecting means for a predetermined length of time after the projectile has departed from its starting place so as to permit stabilization of the projectile with its striker head directed forwardly in its predetermined trajectory.

2. A projectile as claimed in claim 1, in which the said projecting means consists of a spring, and said projection delaying means includes a spring-driven rotor adapted to start rotation after departure of the projectile from its starting place, and a safety device which normally prevents the precursor from being projected, said safety device being controlled by said rotor to permit projection of the precursor only after the initial rotor movement.

3. A projectile as claimed in claim 1, in which the said projection delaying means includes a spring-driven rotor adapted to start rotation after departure of the projectile from its starting place, and a safety device which normally prevents the precursor from being projected, said safety device being controlled by said rotor to permit projection of the precursor only after the rotor has rotated through an angle corresponding to the desired time interval between the start of the rotor and the projection of the precursor, said rotor being concentrically arranged around the said precursor.

4. A projectile as claimed in claim 1, in which the said projection delaying means includes a spring-driven rotor adapted to start rotation after departure of the projectile from its starting place, and a safety device which normally prevents the precursor from being projected, said safety device being eontrolled by said rotor to permit projection of the precursor only after the rotor has rotated through an angle corresponding to the desired time interval between the start of the rotor and the projection of the precursor, said rotor carrying the said fuse cap and fuse in a predetermined eccentric position whereby said fuse cap is brought into alignment with said ring pin after the rotor has turned through a certain angle from its initial position.

HELGE FABIAN ROST. PER. HARRY ELIAS CLAESSON. ROLF ALBIN SVENSSON. 

